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From: ric@cs.arizona.edu (Ric Anderson)
Newsgroups: comp.sys.sequent
Subject: Re: obsolete Sequent software
Message-ID: <1037@caslon.cs.arizona.edu>
Date: 5 Mar 91 18:24:05 GMT
References: <124708@uunet.UU.NET>
Organization: U of Arizona CS Dept, Tucson
Lines: 41

Owning a Sequent has certain been eye opening.  Some things, like the
performance with 100 students beating on it, are really nice.

Others, like
	1.  Lack of Sticky Bit enforcement on directories;
	2.  rejecting NFS file requests from users in more than 8
	    groups (even if the user OWNS the file in question);
	3.  no NFS record locking;
are a continuing problem.

Dynix/ptx does not seem to address item 2 or 3 above, since ptx
allegedly is still based on the same NFS that Dynix 3.0.17 has.  I
don't know about item 1 under ptx.

Of these, I think item 1 is the biggest problem, because without it,
any user can remove a file in a world writable directory.  With Sticky
Bit enforcement, you can only remove/rename files you own.  Since some
directories (tmp, /usr/tmp,...) don't work well if they are not world
writable, Sticky Bit enforcement on such directories is a must.

Item 2 is also serious, because it constantly frustrates people.  Most
older NFS implementations truncate the request to 8 groups, so you can
still get to your own files across NFS, but Sequent's draconian
approach disallows even that civility.

Item 3 is a nuisance for us, but it would be nice to have it fixed.

We knew Sequent had an older BSD implementation when we acquired the
system.  We did not realize the seriousness of the NFS deficiencies.  I
don't know if such knowledge would have changed the purchase decision,
but I have no doubt it would have weighed heavily against Sequent.

We have certainly learned some important additional questions to ask
potential vendors as a result of this experience :-(
Ric

Ric Anderson                    Member of the Technical Staff
University of Arizona           Internet: ric@cs.arizona.edu
Department of Computer Science  UUCP: uunet!arizona!ric
Gould-Simpson Room 721          Bitnet: ric%cs.arizona.edu@arizona.bitnet
Tucson, Arizona 85721           AT&T: (602) 621-4048